Arizona’s dry heat may be deadlier than we thought

Added: 2026-06-07

[00:00:00]Walking home from work on a Wednesday in June, Dan, who lives in Phoenix, is not ready for the heat.

[00:00:08]>> It's been like that for a while.

[00:00:09]>> The Southern California native says adjusting to Arizona's heat took time.

[00:00:14]But, >> I'd rather have a dry heat than humid.

[00:00:16]>> Why is that?

[00:00:17]>> Oh, there's less sweat.

[00:00:19]>> While the dry heat feels different, it isn't any less dangerous.

[00:00:24]>> We can say that extremely hot and dry conditions are found to be just as deadly as hot and humid conditions, but for very different reasons.

[00:00:32]>> Jennifer Vanos is an associate professor at ASU School of Sustainability.

[00:00:37]She co-authored research which examined six heat waves across the globe, including Phoenix's summer of 2023, which shattered heat and death records across the valley.

[00:00:48]>> It's super important to respect the heat and understand that heat affects everyone differently for different reasons.

[00:00:54]>> Vanos says scientists have long relied on a metric called wet bulb temperature to flag deadly heat.

[00:01:01]That heavily weighs humidity.

[00:01:04]But that metric can miss how dangerous dry climates like ours truly are.

[00:01:09]>> We were able to show the deadliness of the Phoenix heat wave that other models might not pick up because they're not focused on those the dangerousness of the dry conditions and how the human body responds to that.

[00:01:21]>> Vanos says shade and even misters can make a big difference in dry heat cities like Phoenix.

[00:01:28]>> I just keep hydrated, you know, stay indoors, you know, go swimming when it when and if I can.

[00:01:35]>> And Vanos says that really every person reacts differently in different kinds of heat. And with the triple-digit temperatures here, she says it's a good idea for all of us living in the valley to check in with our friends, our family, and our neighbors to make sure all of us stay safe this summer. For now, reporting live in Phoenix, Zach Perlatsky for Arizona's Family.